Calculating device.



W. H. ROBERTSON. CALCULATING DEVICE. APPLICATION FILED MAR. 1.9. 1915.

1,286, 1 1 2. Patentd Nov. 26, 1918.

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0 48 (,5 80 99 120 m 2 5e 72 90 no n2 |44 F [7? 1 60 for ra n s'rn'rns ran onion WILLIAM HENRY ROBERTSON, OF DAYTON, OHIO, ASSIGNOR TO THE EDUCATIONAL NOVELTY COMBANY, OF DAYTON, OHIO, A CORPORATION OF OHIO.

CALCULATING DEVICE.

Specification of Letters Patent.

Patented Nov. 26, 191 8.

Application filed March 19. 1915. Serial No. 15,674.

To all whom it may concern not used. for calculating and it is intended to provide a quick and simple method of finding results on the chart by mechanical means thereby relieving the eye of having to follow columns and of making mistakes by locating results at the wrong intersections.

With these and incidental objects in view, the invention consists in certain novel features of construction and combination of parts, the essential elements of which are set forth in the appended specification and a preferred form'of embodiment of which is hereinafter described with reference to the drawings which accompany and form a part of the specification.

Figurel of said drawings shows a modified form oi: embodiment of the invention.

Fig. 2 shows the preferred form of embodiment of the invention.

By reference to the chart shown on plate A in Fig. l, a series of elemental characters such as a series of numbers from 1 to 12 is shown and above this is a table of result characters such as a multiplication table. lit

will be observed that the product of any two numbers of the series can be found on an imaginary line which is the perpendicular bisector of another such line connecting the two numbers of the series; also that this product is located at a distance above the slot in plater-l depending u on the distance between the two numbers of the series.

In Fig. 1 two members D and C are shown pivoted bv a stud D and having studs E and F projecting through a slot in plate A. The edges of these members are shaped into a number of semicircular notches. The two members D and C are movable and are guided by the slot in plate A. When the two studs E and F are moved closer together than shown in Fig. l and are directly over two numbers, a certain two of the semicircular notches will be brought together to form a circular opening. The distance from this opening to the slotwill depend upon the distance apart of the two studs E and F. Also the opening will lie on a line which is the perpendicular bisector of a line connecting the two members. It therefore satisfies the two conditions necessary for locating the product of the two numbers. Hence when the members l3 and C are properly formed, the product of the two members under studs E and F will be indicated by the two notches above which have formed a circle around it. In finding the proper shape for members B and C, experiment and theory both show that for the triangular arrangement of figures shown, the centers of the arcs forming the notches in member B, should all lie on another larger arc of a circle which passes through pivot D and the upper corner of the triangle and the center of stud E, when E is located adjacent to the lower corner of the triangle as shown. From this can also be found the location of the notches in member C. If Fig. 2 were placed directly over Fig. l and in perfect alinement, then the centers of the circles on whose circumference the notches are located, would lie directly under the centers of studs d and K of Fig. 9.

In Fig. 2 is shown the preferred form of the-invention. Instead of having semicircular notches to form acircle around the roduct, a circular hole is shown in a stud L, connected bv links G and H to members B and C. This hole is to indicate results. Studs E and F are also retained directlv adjacent to desired members by a detent M secured to plate A by studs N and O, and pressed upward by springs P and Q. As the studs E and F are moved closer to ether, stud L moves closer to the slot. In Fig. 2 assume temporarilv that all the letters representing studs also represent the projection of the centers of these studs on the surface oi plate A. Then when the distances 5 D .l L J E, K D, K L and K F are all equal, itcan be proven by geometry that if the studs E and F are moved two spaces closer together, then stud L moves one space closer to the horizontal slot. This satisfies the conditions necessary for locating the product of any two numbers adjacent to the studs and F. When a number is to squared, the.

i v stud F must be adjacent to the character at readily as on a' multiplication table.

While the form of the mechanism herein shown and described is admirably adapted to fulfil the objects primarily stated, it is to be understood that it is not intended to confine the invention to the forms of embodiment herein disclosed, for it is susceptible of embodiment in various forms all coming within the scope of theclaims which follow.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a device of the character described the combination with a chart havin a series of elemental characters and a tab e of result characters; of two members, each adapted to be set independently of the other to indicate one of the elemental characters,- the chart having provisions cooperating with the said members for independently guiding the motion of said members with respect to the vchart, and said members coacting together through a common connection independent of the chart to control the indication of a result character corresponding to the setting of said members.

2. In a device of the character described, the combination with a chart having a series of elemental characters and a table of result characters; of two members, each having a sliding connection with the chart and each movable independently of the other whereby each member may be guided and set independently to indicate one of the ele mental characters, and said members coacting together through a common connection independent of the chart to control the indication of a result character corresponding to the setting of said members.

3. In a. device of the character described,

I the combination with a chart having a. se-

ries of elemental characters and a table of result characters; of two members, each having a sliding connection with the chart and each movable independently of the other, whereby each member may be guided and set independently to indicate one of the elemental characters, said members having acommon pivotal connection independent of the chart whereby said members coact together to control the indication of a result v character corresponding to the said setting of the members.

4. In a device of the character described the combination with a chart having a series of elemental characters and a table of result characters, and provided with a guidmg slot; of two members, each-having a connection with the chart through said sl t whereby each member may be guided and I set to indicate one'of said elemental characters, said members having a common pivotal connection independent of the chart whereby said members coact together to control the indication of a result character coring slot; of two members, each having a slidin pin connection with the said slot where y. each member may be guided and set to indicate one of the elemental characters, said members having a common pivotal connection independent of the chart whereby said members coact together to control the indication of a result character corresponding to the setting of the members; and a spring pressed detent coiiperating with the members to yieldingly retain said members in set position.

6. In a device of the character described, the combination with a chart havmg a senes of elemental characters and a table of result characters; of two members having a com.- mon pivotal connection independent of the chart, and each member having an independent sliding connection with the chart and each movable independent of the other whereby each member may b guided and set independently to indicate one of the elemental characters; and links connected together and with the said members and 006peratin to indicate a result character correspondmg to the said setting of the members.

7. In a device of the character described the combination with a chart having a series of elemental characters and a table of result characters and provided with a guiding slot; of two members, having a common pivotal connection independent of the chart and each member having an independent sliding connection with the chart through said slot whereby each member may be guided and ber may be guided when set to indicate oneof the elemental characters; links connected together and with the said members to indicate a result character corresponding to the said setting of the members,'and a spring the character described, 1

pressed detent cooperating with the members to yieldingly retain said members in set position. I

9. In a device of the character described, the combination with a chart having a series of elemental characters anda table of result characters; of four members,pivoted together quadrilaterally and independently of the chart, two of said members having relatively movable connections with the chart adapted to be set to indicate certain of the elemental characters, while the other two members cooperate to indicate a result character corresponding to the setting of said members.

10. In a device of the character described, the combination Witha chart having a series of elemental characters and a table of result characters, and provided with a guiding slot; of four members, pivoted together quadrilaterally and independently of the chart, two of said members having a sliding connection with the chart through said slot whereby each of the two said members may beguided when set to indicate one of the elemental characters, While the other two members cooperate to indicate a result character corresponding to the setting of said members.

11. In a device of the character described, the combination with a chart having a series of elemental characters and a table of result characters, and provided with a guiding slot; of four members, pivoted together quadrilaterally and independently of the chart, two of said members-having pin connections with said chart through said slot, whereby each of the two said members may be guided when set to indicate one of the elemental characters, while the other two members cooperate to indicate a result character corresponding to'the setting of said memi bers; and a spring pressed detent cooperating with said pin connections to yieldingly retain said members in set position.

In testimony whereof I aflix my signature in the presence of two witnesses.

WILLIAM HENRY ROBERTSON. Witnesses: F. E. HAMmroN,

S. C. EDQUTER. 

